Integrating C Functions with Python using the C API

A Step-by-Step Tutorial

Photo by Fahim Muntashir on Unsplash

Python is a versatile programming language known for its simplicity and extensive ecosystem of libraries. However, in situations where performance is critical, integrating efficient C code with Python can provide significant speed improvements. In this tutorial, we’ll explore how to build a C function and use it in Python using the C API, leveraging the best of both worlds. Let’s get started!

Prerequisites

To follow along with this tutorial, you’ll need the following:

• Basic knowledge of C programming language
• Python installed on your system
• A C compiler (such as gcc or clang) installed on your system
• Familiarity with the command line or terminal

Step 1: Creating the C Function

First, let’s create a simple C function that calculates the factorial of a given integer. Create a new file named factorial.c and add the following code:

#include <stdio.h>
long long factorial(int n) {
    if (n == 0 || n == 1) {
        return 1;
    }
    return n * factorial(n - 1);
}